1. Technical Field of Invention 70/91
This invention relates to a door lock and more particularly to such a door lock for a sliding glass door with automatic latching capability.
2. Background of the Invention
Sliding doors offer many benefits to building functionality. This is particularly true when the sliding doors are constructed of mostly glass. Glass sliding doors are quite popular as they let in maximum amounts of light yet offer decent security and safety. Latching of sliding doors has been difficult to design given the conflicting priorities presented. A few of the priorities are: egress/ingress, security, safety, and ease of use. Everyone would like to have a door that was easy to open from the inside, easy to secure for the outside, and impervious to vandals. Unfortunately, many of these functions are at odds when designers try to satisfy all priorities. Currently, the standard for sliding glass doors is a pull handle on both inside and outside, a lock engage-able and release-able only from the inside, and a inhibit lever to prohibit releasing the lock when the inhibit lever is engaged without disengaging the inhibit lever. Additionally, keyed locks are also typically used to allow access from the outside when the inhibit or night latch is engaged. A safety problem has been identified that can cause undue risks to young children, pets, or compromised adults. The safety problem occurs typically when the sliding door is slid closed the lock may or may not have been set. It is easy for most functional adults to remember to close the door when required (when a pool or similar hazard is beyond the door). It is also easy to check from a distance if the door is slid closed but the lock is impossible to verify (locked/unlocked) from any distance and most often is only checked by a physical pull on the door handle. Some recent designs offer auto closing and independent auto latching however these are expensive and difficult to operate and may cause a fire hazard to shorter individuals unable to operate the raised release during an emergency. Previous attempts to latch sliding door mechanisms suffered from internal mechanism binding and an inability to operate from both inside and outside. What is needed is an auto-latching mechanism for sliding door hardware without additional operational requirements.